I shoot everything from Nikon Full frame to an XZ-1 , and have used the D700 in the past , now mainly a D4 and D800e. The stylus 1 would make a great back up camera to your D700 but the loss in image quality would make me hesitant to use it as a primary camera especially for critical work as yours.You have some lovely images in your gallery btw.

Like many others I dislike the weight and size factor of the pro DSLRs and after much deliberation and thought ended up with a Fuji XE-1. Its far from perfect but the 55-200( FF equivalent 84-300) is stunning for its size and weight , optically it can compete with the 70-200 AFS. To be truthful the original release of these cameras was woeful , superb glass, great sensor and lousy everything else. A few firmware updates later and they outperform many APSC cameras.With an adapter all Nikon Lenses can be used with same FOV as on APSC models.

One other item to consider is responsiveness and battery life ,EVFs chew batteries and nothing beats a 100% view glass pentaprism for framing an image.